If you're looking for Gordo, that's the stables cat. You might find him somewhere around the Robert's Stables. If you do find him, press X at the tree, you're sure to get him!

A2:

Gordon the cat is marked as an orange dot on the map, as there is many orange dots on the map you might have to go to all until you fing gordon. the tree has an orange marker on it and then you have to press X so you can take gordon back to his owner. hope this helps